Craftsmen, handymen, and other users of screw type fasteners have, since shortly after the invention of such fasteners, been frustrated by the difficulty posed by the need to occasionally install them in locations that are not easily accessed. Prior art is extensive, and in and of itself is evidence of the long held and widespread desire of artisans and the common handyman to devise a simple, inexpensive and versatile solution to this problem.
As early as 1870, U.S. Pat. No. 99,781 to Martyn demonstrates a solution that involves the employment of a cylindrical sleeve, actuated by a spring, to hold the screw in a favorable position with the driver head while the screw is driven, and to allow the sleeve to retract out of the way as the screw head comes into contact with the surface. U.S. Pat. No. 1,593,233 to Wilson in 1926 and U.S. Pat. No. 3,288,185 to Clark in 1966 are other examples of this approach. These devices are deficient in two basic ways. First, because the sleeve does not positively hold the screw to the driver head, the screw can fall free when the device is angled downward, and in all but an upward orientation the screw is so loosely in contact with the driver head that damage to the kerf is likely as the driving process occurs. Secondly, in order to work even reasonably well, the diameter of the sleeve must closely match the diameter of the screw head, necessitating multiple devices if it is to be used with a variety of screw sizes.
To overcome these deficiencies, inventors have employed a variety of remedies that involve flexible, resilient members that springably engage the screw head as a means of retaining it to the driver. U.S. Pat. No. 845,978 to Rappelee in 1907 employs a combination of a compression spring with a pair of screw holding jaws that are sleeved to the driver, the tips of said jaws being inwardly formed in a convex manner. This device, however, relies on a specifically modified driver and a permanent attachment of the device, the result being not only the requirement of a modification to the driving tool, but a modification that significantly weakens it. Additionally, the invention in no way envisions anything other than a device that must be permanently and specifically matched to the driver, thus eliminating the possibility of portability or minor adjustment to accommodate different fasteners.
U.S. Pat. No. 1,698,521 to Wood in 1929 combines the elements of a spring actuated guiding sleeve with springable fingers, said fingers being formed at the tips in a manner that lends itself to the retaining of a screw head. This invention, however, also relies on a driving tool that is specifically designed or modified to the requirements of the device, and as such is neither portable nor adjustable in the cause of dealing with different sizes and types of screws. Additionally, the sleeve, in order to be effective, as mentioned earlier, must closely match the diameter of the screw head. Furthermore, the sleeve presents an ineffective enclosure that prevents visual access to the driver head, thus making more difficult the alignment of the kerf with the driver head. Perhaps most significant of the drawbacks of this invention is its complexity, which involves the costly manufacture and assembly of multiple components that must have closely matched tolerances.
U.S. Pat. No. 1,712,196 to Burger et al. in 1929 features a sleeve with attached springable fingers, the tips of which are formed in a manner that allows for the insertion and retention of a screw head. The deficiencies of this invention are several. As with Wood, the sleeve not only has limited use unless its size is closely matched to that of the screw head, it presents an impediment to the visual alignment of the kerf with the screw head that often leads to the unnecessary and annoying need to “jockey” the two together. Additionally, though not as complex as Wood, it requires the costly manufacture and assembly of parts that demand close tolerances. Furthermore, this invention in no way envisions any means of actuation of the device on the driver other than manually sliding it to and fro, and therefore will not self grasp a fastener when it is being removed from a difficult to access location.
U.S. Pat. No. 2,633,168 to Mahaffey in 1953 describes a spring actuated cylinder with extending springable fingers, the tips of which are formed inward to allow for the retention of a screw head. This invention fails in several ways. It involves a fixed collar attached to the driver, abutting a spring, around which is formed a cylinder with extending fingers. Thus, a collar must be pressed or affixed in some manner at an exact location on the driver, and the cylinder formed around the collar and spring in such a manner that the collar is no longer accessible should it loosen, require minor adjustment, or it be desired to remove the entire device from the particular driver and install it on another. Additionally, the inwardly turned tips of the grasping fingers preclude the use of this device with flat head fasteners. Indeed, with virtually all head types except for round heads of a closely matched size, the invention performs poorly. Another criticism of this invention is that significant scarring of the surface is likely to occur as the screw is driven home and the tips of the fingers are forced outward by the force of the advancing screw.